1972 datsun 240z ammeter not working. Easy fix or should i get a used one?

[siteunseen]

24 inches is plenty. You can tuck and hide the extra wire. Mine have been replaced too. I see now I have room to go to an opposite post battery. Get the hot out from under the fender.

 

[jalexquijano]

those wires are too long. I am looking for a 24 inch wire.

[siteunseen]

I'm not trying to sell you my wires. 

I put that up for you to see how long mine were and show how you can tuck them under the battery tray.  

Any auto parts store should have a 24" negative battery cable.  

 

[jalexquijano]

What is the gauge for the firewall ground cable? I know its 9 inches long but what gauge? This is the one that is fastened to my negative pole and that i wish to replace.

Edited February 11, 2019 by jalexquijano

[jalexquijano]

On 12/31/2018 at 10:37 AM, SteveJ said:

 

Those are blanket statements and not really accurate.

1. The ammeter is designed to indicate charge/discharge of the battery. The ammeter is situated between the battery and alternator, and most loads are on the alternator side of the ammeter. If the ammeter is on the positive side, the alternator is charging the battery and/or your brake lights/hazard lights are drawing current.
2. Make sure you have a good battery. The specified alternator and the wiring harness are not designed to charge a dead battery.
3. If the ammeter has failed completely, typically the car will not start since current will not flow through the ammeter. For starting the car, power goes from the battery, through the fusible link and ammeter, and to the ignition switch.
4. If the alternator has failed, the electrical system is relying solely upon the battery, and the battery will discharge.
5. If the voltage regulator has failed, typically the battery will reverse power the alternator when the car is off, and the battery will discharge.
6. The FSM describes alternator and voltage regulator testing. See EE-18 for the alternator test and EE-22 for the start of the regulator testing. Of course, you can purchase a clamp DC ammeter to place over the battery cable to simplify testing. (This means you don't need to use the resistor shown in figure EE-55 if you use the clamp DC ammeter.)
7. The voltage reading of 14.5 would be at 2500 RPM, and that is not a go/no-go voltage. A voltage between 14 and 15 VDC at 2500 RPM should be fine. As the FSM states, the alternator should show 12.5 or higher at 1000 RPM when doing the test as described in the manual.

Ahmeter is  stuck again at 3/4 positive side. Even with the car engine off its stuck. Any clues on solving this matter again? Its kind of hard to get a working replacement nowadays. 

On 12/31/2018 at 1:44 PM, Mark Maras said:

@jalexquijano Happy New Year Buddy. Glad you coerced the gauge back into working condition again. A word of caution. The problem will reoccur and too many thumps on the plastic faceplate will eventually crack it. V.O.E. Don't want to hijack the thread but how's your Z running these days?